Hereinafter, a machine to machine (M2M) communication environment will be described in brief.
Machine-to-Machine (M2M) refers to communication between an electronic device and another electronic device. In a broad sense, M2M refers to wire or wireless communication between electronic devices or communication between a machine and a device controlled by a person. However, it is general that M2M recently refers to wireless communication between electronic devices, i.e., devices performed without control of a person.
In the early 1990s when M2M communication has been introduced, M2M communication has been recognized as remote control or telematics and M2M communication markets have been very restrictive. However, M2M communication markets have received attention all over the world since M2M communication had been able to grow rapidly for last several years. Particularly, M2M communication has exerted its great influence at point of sales (POS) and security related application markets in the fields of fleet management, remote monitoring of machine and facilities, measurement of working time on construction machine facilities, and smart meter automatically measuring heat or the use of electricity. It is expected that M2M communication will be used for various purpose of uses in association with the existing mobile communication and low power communication solutions such as wireless high-speed Internet, Wi-Fi, and Zigbee and that its coverage will be extended to business to consumer (B2C) markets without limitation to business to business (B2B) markets.
In the M2M communication age, since all machines provided with a subscriber identity module (SIM) card may be able to perform data transmission and reception, they may remotely be controlled. For example, M2M communication technologies may be used for many machines and equipments such as cars, trucks, trains, containers, vending machines, and gas tanks. In this way, application ranges of M2M communication technologies are very broad.
According to the related art, since it was general that a user equipment was controlled separately, communication between a base station and a user equipment has been performed by a one-to-one communication mode. Supposing that many M2M devices perform communication with a base station through such a one-to-one communication mode, network overload will be caused by signaling generated between each of the M2M devices and the base station. As described above, if M2M communication is rapidly spread and widely used, a problem may occur due to overhead caused by communication between M2M devices or between each of the M2M devices and the base station.
Also, since a person does not involve in operations of the M2M devices in the M2M system, an abnormal power outage event for the M2M devices may occur. In this case, a power outage event may occur in most of M2M devices at a point to which the corresponding M2M device belongs.
If a power outage event occurs, the M2M devices should report such a power outage event to the base station. For example, M2M devices in an idle mode may perform a ranging process to report the power outage event. In this case, it is likely that collision between the M2M devices may occur.
If collision between the M2M devices occurs, a collision resolution process is performed to solve the collision. Accordingly, if an abnormal power outage event occurs, problems may occur in that unnecessary power consumption is increased in the M2M device and efficiency of a system resource may be deteriorated.